Combined cracking and selective hydrogen combustion for catalytic cracking

ABSTRACT

A catalyst system and process for combined cracking and selective hydrogen combustion of hydrocarbons are disclosed. The catalyst comprises:
         (1) at least one solid acid component,   (2) at least one metal-based component comprised of
           (i) at least one of oxygen and sulfur   (ii) one or more elements from Groups 5–15 of the Periodic Table of the Elements; and   (iii) one or more elements from at least one of
               (a) Groups 1–2 and   (b) Group 4; of the Periodic Table of the Elements; and   
               
           (3) at least one of at least one support, at least one filler and at least one binder. The process is such that the yield of hydrogen is less than the yield of hydrogen when contacting the hydrocarbons with the solid acid component alone.

BACKGROUND OF THE INVENTION FIELD OF THE INVENTION

The present invention relates to a novel catalyst composition and itsuse in a novel hydrocarbon cracking process. The catalyst isparticularly useful in reducing the concentration of hydrogen incracking products.

DISCUSSION OF BACKGROUND INFORMATION

Current cracking technologies for the production of light olefins (e.g.ethylene, propylene and, optionally, butylenes), gasoline and othercracked products such as light paraffins and naphtha can be classifiedinto the two categories of thermal cracking (also known as steamcracking) and catalytic cracking. While these technologies have beenpracticed for many years and are considered the workhorses forlight-olefin production, both have disadvantages.

Steam or thermal cracking, a robust technology that does not utilizecatalyst, produces the more valuable ethylene as the primary lightolefin product. It is particularly suitable for cracking paraffinicfeedstocks to a wide range of products including hydrogen, lightolefins, light paraffins, and heavier liquid hydrocarbon products suchas pyrolysis gasoline, steam cracked gas oil, etc. However, steamcracking is an expensive, complex technology due to required specialconstruction material to sustain high cracking temperatures (˜850° C.)and high energy input. Sulfur addition is required to passivate thefurnace metal surfaces on a continuous basis, creating such undesirableside effects as environmental and product contamination. Steam crackingis not considered to be suitable for cracking feeds containing highconcentrations of light olefins as it makes high levels of low valueheavy by-products due to the more reactive nature of the olefin feeds.In addition, steam cracking makes a relatively low amount of propylene,and, therefore, is not considered suitable for meeting the anticipatedgrowing demand for propylene in the future. Also, steam crackingrequires steam dilution to control product selectivity and to maintainan acceptable run length; steam dilution is costly in terms of capitalinvestment and energy consumption.

Current catalytic cracking technologies employ solid acid catalysts suchas zeolites to promote cracking reactions. Unlike steam crackingtechnology, propylene is the primary light olefin product of catalyticcracking. Accordingly, catalytic cracking would be considered as themain source for growing propylene demand. Catalytic cracking can beclassified into the following two general categories. The first categoryis Fluid Catalytic Cracking (FCC), which is the preferred refiningprocess for converting higher boiling petroleum fractions into lowerboiling products, such as gasoline, cracked naphtha and light olefins.The FCC catalyst of fine particles acts like a fluid and circulates in aclosed cycle between a cracking reactor and a separate regenerator. Ingeneral, FCC catalysts can be classified into two categories—FCC basecatalysts and FCC additive catalysts. Typical FCC catalysts contain thebase catalysts which comprise a zeolite component and a matrixcomponent. The zeolite is a major contributor for the catalyst activity,selectivity and stability. Examples of the zeolite component include Yzeolite and beta zeolite. The zeolite usually is treated with variousmodifications such as dealumination, rare earth exchange, phosphoroustreatment, etc. Examples of typical matrix materials include amorphouscompounds such as silica, alumina, silica-alumina, silica-magnesia, andclays such as kaolinite, halloysite or montmorillonite. The matrixcomponent can serve several purposes. It can be used to bind the zeolitecomponent to form catalyst particles. It can serve as a diffusion mediumfor the transport of feed and product molecules. It also can act as afiller which dilutes the zeolite particles to moderate the catalystactivity. In addition, the matrix can help heat transfer.

Some FCC catalysts also contain FCC additive catalyst(s), including, byway of non-limiting examples, octane-boosting additive, metalpassivation additives, SOx reduction additives, NOx reduction additives,CO oxidation additives, coke oxidation additives, etc. The additivecatalyst(s) can be either incorporated into the base catalyst matrix orused as separate catalyst particles. When used as separate catalystparticles, the additive catalyst(s)will contain in addition to thecatalytic active components their own matrix materials, which may or maynot be the same as the base catalyst matrix. Examples (U.S. Pat. No.4,368,114, which is incorporated herein by reference in its entirety) ofthe main catalytic components for octane-boosting additive catalystsinclude ZSM-5 zeolite, ZSM-11 zeolite, beta zeolite, etc. Examples ofSOx reduction additives include magnesia, ceria-alumina, rare earths onalumina, etc. Examples of CO oxidation additives include platinum and/orpalladium either directly added to the base catalyst at trace levels ordispersed on a support such as alumina or silica alumina (U.S. Pat. Nos.4,072,600 and 4,107,032, which are incorporated herein by reference intheir entirety). Non-limiting examples of coke oxidation promotersinclude lanthanum and iron embedded in the base catalyst (U.S. Pat. No.4,137,151, which is incorporated herein by reference in its entirety).Examples of metal passivation additives include barium titanium oxide(U.S. Pat. No. 4,810,358, which is incorporated herein by reference inits entirety), calcium-containing additives selected from the groupconsisting of calcium-titanium, calcium-zirconium,calcium-titanium-zirconium oxides and mixtures thereof (U.S. Pat. No.4,451,355, which is incorporated herein by reference in its entirety),and antimony and/or tin on magnesium-containing clays (U.S. Pat. No.4,466,884, which is incorporated herein by reference in its entirety).

For a riser FCC unit, fresh feed contacts hot catalyst from theregenerator at the base of the riser reactor. The cracked products aredischarged from the riser to pass through a main column, which producesseveral liquid streams and a vapor stream containing hydrogen, methane,ethane, propane, butane, and light olefins. The vapor stream iscompressed in a wet gas compressor and charged to the unsaturated gasfacility for product purification. Another technology in this categoryis moving bed cracking or Thermoform Catalytic Cracking (TCC). The TCCcatalyst is in the form of small beads, which circulate between areactor and a regenerator in the form of a moving bed. A furtherdescription of the FCC process may be found in the monograph, “FluidCatalytic Cracking with Zeolite Catalysts,” P. B. Venuto and E. T.Habib, Marcel Dekker, New York, 1978, incorporated by reference.

The second category of catalytic cracking is catalytic cracking ofnaphtha, the main purpose of which is the generation of light olefins.Either FCC-type reactor/regenerator technology (U.S. Pat. No. 5,043,522,which is incorporated herein by reference in its entirety), or fixed-bedreactor technology (EP0921175A1 and EP0921179A1, which are incorporatedherein by reference in their entirety), can be used. The products, whichinclude liquid streams and a vapor stream of hydrogen, methane, ethane,propane, butane, and light olefins go through a series of treatmentssimilar to that for the FCC products.

As pointed out above, current cracking technologies typically producevapor streams containing mixtures of hydrogen, light paraffins (e.g.methane, ethane, propane, and optionally, butanes) and light olefins. Insome cases, such as ethane cracking, hydrogen is recovered in highpurity as a valued product. In many other cases, such as steam crackingof naphtha, FCC of gas oil, catalytic cracking of olefinic naphtha,etc., hydrogen is undesirable due to the difficulty of separating H₂from the light olefins (ethylene and propylene). The presence of even amoderate quantity of H₂ in cracked products necessitates such expensiveequipment as multi-stage gas compressors and complex chill trains, whichcontribute significantly to the cost of olefin production. If crackedproducts could be produced with minimal or no hydrogen in the reactoreffluent, a significant cost saving could be realized for grassrootsplants and for debottlenecking existing plants, and lower olefinmanufacturing cost could be realized.

Conventional approaches to deal with the hydrogen issue have focused onpost-reactor separation. That is, attempts have been made to use variousreaction and/or separation techniques such as pressure swing adsorptionor membranes to remove hydrogen from the olefins. However, thesetechnologies suffer from a few disadvantages. First, they mostly operateat relatively high pressure (>7 atmospheres), which does not help reducethe burden on the compressors. Second, these technologies are expensive.Third, their performance of separating the olefin product into a H₂-richstream and a H₂-poor stream is often unsatisfactory. A typical problemhas been the loss of olefins to the hydrogen-rich stream due to anincomplete separation. As a result, many commercial plants still employthe complex and costly high-pressure cryogenic separation.

U.S. Pat. No. 4,497,971, which is incorporated herein by reference inits entirety, relates to an improved catalytic process for the crackingand oxidative dehydrogenation of light paraffins, and a catalysttherefor. According to this patent, a paraffin or mixtures of paraffinshaving from 2 to 5 carbon atoms is oxidatively dehydrogenated in thepresence of a cobalt-based catalyst composition which not only hasoxidative dehydrogenation capabilities but also has the capability tocrack paraffins having more than two carbon atoms so that a paraffinsuch as propane can be converted to ethylene. If the feed to theoxidative dehydrogenation process contains paraffins having more thantwo carbon atoms, some cracking of such paraffins will occur at theconditions at which the oxidative dehydrogenation process is carriedout.

U.S. Pat. No. 4,781,816, which is incorporated herein by reference inits entirety, relates to a catalytic cracking process and to a processfor cracking heavy oils. It is an object of the disclosed invention toprovide a process for cracking hydrocarbon-containing feedstocks, whichcontain vanadium compounds as impurities. According to this patent, thefeedstream to be treated contains at least about 5 wppm vanadium. Thecatalyst comprises a physical mixture of zeolite embedded in aninorganic refractory matrix material, and at least one oxide of a metalselected from the group consisting of Be, Mg, Ca, Sr, Ba and La(preferably MgO) on a support material comprising silica.

U.S. Pat. No. 5,002,653, which is incorporated herein by reference inits entirety, relates to an improved catalytic cracking process using acatalyst composition for use in the conversion of hydrocarbons tolower-boiling fractions. More particularly, the invention comprises aprocess for using a dual component catalyst system for fluid catalyticcracking, which catalyst demonstrates vanadium passivation and improvedsulfur tolerance. The catalyst comprises a first component comprising acracking catalyst having high activity, and, a second component, as aseparate and distinct entity, the second component comprising acalcium/magnesium-containing material in combination with amagnesium-containing material, wherein the calcium/magnesium-containingcompound is active for metals trapping, especially vanadium trapping.

U.S. Pat. No. 5,527,979, which is incorporated herein by reference inits entirety, relates to a catalytic oxidative dehydrogenation processfor alkane molecules having 2–5 carbon atoms. It is an object of thedisclosed invention to provide a process for dehydrogenation of alkanesto alkenes. More particularly, the invention comprises a process of atleast two reactors in series, in which an alkane feed is dehydrogenatedto produce alkene and hydrogen over an equilibrium dehydrogenationcatalyst in a first reactor, and the effluent from the first reactor,along with oxygen, is passed into a second reactor containing a metaloxide catalyst which serves to selectively catalyze the combustion ofhydrogen. At least a portion of the effluent from the second reactor iscontacted with a solid material comprising a dehydrogenation catalyst tofurther convert unreacted alkane to additional quantities of alkene andhydrogen. The equilibrium dehydrogenation catalyst comprises at leastone metal from Cr, Mo, Ga, Zn and a metal from Groups 8–10. The metaloxide catalyst comprises an oxide of at least one metal from the groupof Bi, In, Sb, Zn, Tl, Pb and Te.

U.S. Pat. No. 5,530,171, which is incorporated herein by reference inits entirety, relates to a catalytic oxidative dehydrogenation processfor alkane molecules having 2–5 carbon atoms. It is an object of thedisclosed invention to provide a process for dehydrogenation of alkanesto alkenes. More particularly, the invention comprises a process ofsimultaneous equilibrium dehydrogenation of alkanes to alkenes andcombustion of the hydrogen formed to drive the equilibriumdehydrogenation reaction further to the product alkenes. The processinvolves passing the alkane feed into a reactor containing both anequilibrium dehydrogenation catalyst and a reducible metal oxide,whereby the alkane is dehydrogenated and the hydrogen produced issimultaneously and selectively combusted in oxidation/reduction reactionwith the reducible metal oxide. The process further comprisesinterrupting the flow of alkane into the reaction zone, reacting thereduced metal oxide with a source of oxygen to regenerate the originaloxidized form of the reducible metal oxide, and resuming the reaction inthe reaction zone using the regenerated from of the reducible metaloxide. The dehydrogenation catalyst comprises Pt or Pd, and thereducible metal oxide is an oxide of at least one metal from the groupof Bi, In, Sb, Zn, Tl, Pb and Te.

U.S. Pat. No. 5,550,309, which is incorporated herein by reference inits entirety, relates to a catalytic dehydrogenation process for ahydrocarbon or oxygenated hydrocarbon feed. More particularly, theinvention comprises a process of contacting the feed with a catalyst bedcomprising a dehydrogenation catalyst and a porous coated hydrogenretention agent in which the dehydrogenation catalyst produces a productstream of a dehydrogenated product and hydrogen and the porous coatedhydrogen retention agent selectively removes, adsorbs or react with someof the hydrogen from the product stream, removing the reaction productsfrom the reaction chamber, removing the adsorbed hydrogen from thehydrogen retention agent or oxidizing the reduced hydrogen retentionagent to regenerate the hydrogen retention agent, and using theregenerated hydrogen retention agent for reaction with feed.

U.S. Pat. No. 4,466,884, which is incorporated herein by reference inits entirety, relates to a catalytic cracking process for feedstockshaving high metals content such as vanadium, nickel, iron and copper.More particularly, the invention comprises a process of contacting thefeed with a catalyst composition comprising a solid cracking catalystand a diluent containing antimony and/or tin. The solid crackingcatalyst is to provide good cracking activity. The diluent can becompound or compounds having little activity such as magnesiumcompounds, titanium compounds, etc. The function of the antimony and/ortin in the diluent is to react with the nickel or vanadium in thefeedstocks to form inert compounds thereby reducing the deactivatingeffects of nickel and vanadium on the solid cracking catalyst.

U.S. Pat. No. 4,451,355, which is incorporated herein by reference inits entirety, relates to a hydrocarbon conversion process for feedstockshaving a significant concentration of vanadium. More particularly, theinvention comprises a process of contacting the feed having asignificant concentration of vanadium with a cracking catalystcontaining a calcium containing additive selected from the groupconsisting of calcium-titanium, calcium-zirconium,calcium-titanium-zirconium oxides and mixtures thereof. A preferredcalcium additive is a calcium titanate perovskite (CaTiO3) or calciumzirconate (CaZrO3) perovskite. It is theorized that addition of thecalcium-containing additive prevents the detrimental vanadiuminteraction with the zeolite in the cracking catalyst by acting as asink for vanadium.

A significant need exists for a cracking technology that overcomes thepreviously discussed disadvantages of present, commercial crackingtechnology due to of the presence of hydrogen in cracked products.

SUMMARY OF THE INVENTION

One aspect of the present invention relates to a catalyst systemcomprising

(1) at least one solid acid component,

(2) at least one metal-based component comprised of

-   -   (iii) at least one of oxygen and sulfur    -   (iv) one or more elements from Groups 5–15 of the Periodic Table        of the Elements; and    -   (v) one or more elements from at least one of        -   (a) Groups 1–2 and        -   (b) Group 4; of the Periodic Table of the Elements; and            at least one of at least one support, at least one filler            and at least one binder.

According to another aspect of the present invention, the solid acidcatalyst is in physical admixture with, or chemically bound to, themetal-based component. The elements from (i), (ii) and (iii) can bechemically bound, both the elements between and within the groups. Forexample, it would be within the scope of the present invention for twoor more elements from Groups 1 and 2 to be chemically bound to eachother, as well as, chemically bound to the element(s) from Groups 5–15.Alternatively, the chemical binding can be only between elements ofdifferent groups and not between elements within the same group, i.e.,two or more elements from Groups 1 and 2 being in admixture with eachother but chemically bound to the element(s) from Groups 5–15.

The solid acid component can comprise at least one of at least onesupport, at least one filler and at least one binder. In another aspect,the solid acid component can comprise at least one of one or moreamorphous solid acids, one or more crystalline solid acids and one ormore supported acids. In one embodiment of the present invention, thesolid acid catalyst comprises at least one molecular sieve. In apreferred embodiment, the molecular sieve comprises at least one ofcrystalline silicates, crystalline substituted silicates, crystallinealuminosilicates, crystalline substituted aluminosilicates, crystallinealuminophosphates, crystalline substituted aluminophosphates,zeolite-bound-zeolite, having 8- or greater-than-8 membered oxygen ringsin framework structures. In another embodiment of the present invention,the solid acid component is at least one zeolite. The zeolite cancomprise at least one of faujasite and MFI. The faujasite zeolite can beY zeolite or modified Y zeolites such as dealuminated Y zeolite, highsilica Y zeolite, rare earth-exchanged Y zeolite, etc. The MFI zeolitecan be ZSM-5 zeolite or modified ZSM-5 zeolites such as phosphroustreated ZSM-5 zeolite and lanthanum treated ZSM-5 zeolite. In anotherembodiment of the present invention, the solid acid component can alsobe conventional FCC catalysts including catalysts containing zeolite Y,modified zeolite Y, Zeolite beta, and mixtures thereof, and catalystscontaining a mixture of zeolite Y and a medium-pore, shape-selectivemolecular sieve species such as ZSM-5, or a mixture of an amorphousacidic material and ZSM-5. Such catalysts are described in U.S. Pat. No.5,318,692, incorporated by reference herein.

In a further aspect of the present invention, the metal-based componentcomprises at least one perovskite crystal structure. Furthermore, themetal-based component can comprise at least one of at least one support,at least one filler and at least one binder.

In another aspect of the present invention, the element(s) from Groups1and 2 is (are) at least one of lithium, sodium, potassium, rubidium,cesium, beryllium, magnesium, calcium, strontium, and barium.

In another aspect of the present invention, the element(s) from Group 4are, preferably, at least one of titanium, zirconium and hafnium.

In another aspect of the present invention, preferably, the element(s)from Groups 5–15 is (are) at least one of vanadium, chromium, manganese,iron, cobalt, nickel, copper, zinc, boron, aluminum, phosphorous,gallium, germanium, niobium, molybdenum, ruthenium, rhodium, palladium,silver, indium, tin, antimony, tungsten, rhenium, iridium, platinum,gold, lead and bismuth.

In another aspect of the invention, the oxygen is preferred.

The weight ratio of solid acid component to the total weight of themetal-based component can be about 1000:1 to 1:1000. Preferably, thisratio is about 500:1 to 1:500. Most preferably, this ratio is about100:1 to 1:100.

According to another aspect of the present invention, a process fortreating a hydrocarbon feedstream comprises simultaneously contactingthe feedstream under cracking conditions with a catalyst systemcomprising

(1) at least one solid acid component,

(1) at least one metal-based component comprised of

-   -   (i) at least one of oxygen and sulfur    -   (ii) one or more elements from Groups 5–15 of the Periodic Table        of the Elements; and    -   (iii) one or more elements from at least one of        -   (a) Groups 1–2 and        -   (b) Group 4; of the Periodic Table of the Elements; and

(3) at least one of at least one support, at least one filler and atleast one binder.

It is believed that the inventive catalyst system is unique in that,among other things, it permits simultaneous catalytic cracking ofhydrocarbon feedstreams to cracked products and combustion of resultanthydrogen to water. Preferably, the hydrogen combustion comprisesselective hydrogen combustion. The selective hydrogen combustion can beanaerobic without the feeding of free-oxygen containing gas to thereaction, or it can be conducted with the feeding of free-oxygencontaining gas.

Preferably, the yield of hydrogen is less than the yield of hydrogenwhen contacting said hydrocarbon feedstream(s) with said solid acidcomponent alone under said catalytic reaction conditions. Preferably,the yield of hydrogen is at least 10% less than the yield of hydrogenwhen contacting said hydrocarbon feedstream(s) with said solid acidcomponent alone under catalytic reaction conditions. More preferably,the yield of hydrogen is at least 25% less, more preferably at 50% less,even more preferably at least 75%, more preferably, at least 90%, andmost preferably greater than 99% less than the yield of hydrogen whencontacting said hydrocarbon feedstream(s) with said solid acid componentalone under catalytic reaction conditions.

In a further aspect of the present invention, a catalytic crackingprocess comprises

-   -   (A) charging at least one hydrocarbon feedstream to a fluid        catalytic cracking reactor,    -   (B) charging a hot fluidized cracking/selective hydrogen        combustion catalyst system from a catalyst regenerator to said        fluid catalytic cracking reactor, said catalyst system        comprising:        -   (1) at least one solid acid component,        -   (2) at least one metal-based component comprised of            -   (i) at least one of oxygen and sulfur            -   (ii) one or more elements from Groups 5–15 of the                Periodic Table of the Elements; and            -   (iii) one or more elements from at least one of                -   (a) Groups 1–2 and                -   (b) Group 4; of the Periodic Table of the Elements;                    and        -   (3) at least one of at least one support, at least one            filler and at least one binder.    -   (C) catalytically cracking said feedstream(s) and combusting        resultant hydrogen at 300–800° C. to produce a stream of cracked        products and uncracked feed and a spent catalyst system        comprising said fluid catalytic cracking catalyst and said        selective hydrogen combustion catalyst which are discharged from        said reactor,    -   (D) separating a phase rich in said cracked products and        uncracked feed from a phase rich in said spent catalyst system,    -   (E) stripping said spent catalyst system at stripping conditions        to produce a stripped catalyst phase,    -   (F) decoking and oxidizing said stripped catalyst phase in a        catalyst regenerator at catalyst regeneration conditions to        produce said hot fluidized cracking/selective hydrogen        combustion catalyst system, which is recycled to the said        reactor, and    -   (G) separating and recovering said cracked products and        uncracked feed.

According to yet another aspect of the present invention, a process fortreating a hydrocarbon feedstream comprises contacting at least onehydrocarbon feedstream with a cracking/selective hydrogen combustioncatalyst system under effective catalytic reaction conditions to produceliquid and/or gaseous products comprising cracked hydrocarbons, whereinthe yield of hydrogen is less than the yield of hydrogen when contactingsaid hydrocarbon feedstream(s) with said cracking catalyst alone undersaid catalytic reaction conditions.

DETAILED DESCRIPTION OF THE PRESENT INVENTION

Unless otherwise stated, all percentages, parts, ratios, etc., are byweight.

Unless otherwise stated, certain terms used herein shall have thefollowing meaning:

“paraffins” shall mean compounds having no carbon- carbon double bondsand either the formula C_(n)H_(2n+2) or C_(n)H_(2n), where n is aninteger.

“naphthenes” shall mean compounds having no carbon-carbon double bondsand the formula C_(n)H_(2n), where n is an integer.

“paraffinic feedstream” shall mean hydrocarbon feedstream containingsome amount of paraffins but no olefins.

“olefins” shall mean non-aromatic hydrocarbons having one or morecarbon-carbon double bonds.

“light olefins” shall mean ethylene, propylene, and, optionally,butylenes.

“light paraffins” shall mean methane, ethane, propane, and, optionally,butanes.

“catalyst to oil ratio” shall mean the relative amount of catalyst tohydrocarbon by weight.

“aromatics” shall mean compounds having one or more than one benzenering.

“physical admixture” shall mean a combination of two or more componentsobtained by mechanical (i.e., non-chemical) means.

“chemically bound” shall mean bound via atom to atom bonds.

“cracking/selective hydrogen combustion” shall mean both crackingreaction and selective hydrogen combustion reaction.

“cracking catalyst” shall broadly mean a catalyst or catalysts capableof promoting cracking reactions whether used as base catalyst(s) and/oradditive catalyst(s).

“selective hydrogen combustion catalyst” shall broadly mean a materialor materials capable of promoting or participating in a selectivehydrogen combustion reaction, using either free oxygen or lattice oxygen

“cracking/selective hydrogen combustion catalyst” shall mean a catalystsystem comprised of a physical admixture of one or more crackingcatalysts and one or more selective hydrogen combustion catalysts, orone or more selective hydrogen combustion catalysts chemically bound toone or more cracking catalysts.

“cracking” shall mean the reactions comprising breaking of carbon-carbonbonds and carbon-hydrogen bonds of at least some feed molecules and theformation of product molecules that have no carbon atom and/or fewercarbon atoms than that of the feed molecules.

“selective hydrogen combustion” shall mean reacting hydrogen with oxygento form water or steam without substantially and simultaneously reactinghydrocarbons with oxygen to form carbon monoxide, carbon dioxide, and/oroxygenated hydrocarbons.

“yield” shall mean weight of a product produced per unit weight of feed,expressed in terms of weight %.

“Unless otherwise stated, a reference to an element, compound orcomponent includes the element, compound or component by itself, as wellas in combination with other elements, compounds or components, such asmixtures of compounds.

Further, when an amount, concentration, or other value or parameter isgiven as a list of upper preferable values and lower preferable values,this is to be understood as specifically disclosing all ranges formedfrom any pair of an upper preferred value and a lower preferred value,regardless of whether ranges are separately disclosed.

The particulars shown herein are by way of example and for purposes ofillustrative discussion of the embodiments of the present invention onlyand are presented in the cause of providing what is believed to be themost useful and readily understood description of the principles andconceptual aspects of the present invention. In this regard, no attemptis made to show structural details of the present invention in moredetail than is necessary for the fundamental understanding of thepresent invention, the description making apparent to those skilled inthe art how the several forms of the present invention may be embodiedin practice.

The present invention relates to a catalyst system for treating ahydrocarbon feedstream. Such feedstream could comprise, by way ofnon-limiting example, hydrocarbonaceous oils boiling in the range ofabout 221° C. to about 566° C., such as gas oil, steam cracked gas oiland residues; heavy hydrocarbonaceous oils comprising materials boilingabove 566 C.; heavy and reduced petroleum crude oil, petroleumatmospheric distillation bottom, petroleum vacuum distillation bottom,heating oil, pitch, asphalt, bitumen, other heavy hydrocarbon residues,tar sand oils, shale oil, liquid products derived from coal liquefactionprocesses, and mixtures therefore. Other non-limiting feedstream couldcomprise steam heating oil, jet fuel, diesel, kerosene, gasoline, cokernaphtha, steam cracked naphtha, catalytically cracked naphtha,hydrocrackate, reformate, raffinate reformate, Fischer-Tropsch liquids,Fischer-Tropsch gases, natural gasoline, distillate, virgin naphtha, C₅₊olefins (i.e., C₅ olefins and above), C₅₊ paraffins, ethane, propane,butanes, butenes and butadiene. The present invention is also useful forcatalytically cracking olefinic and paraffinic feeds. Non-limitingexamples of olefinic feeds are cat-cracked naptha, coker naptha, steamcracked gas oil, and olefinic Fischer-Tropsch liquids. Non-limitingexamples of paraffinic feeds are virgin naptha, natural gasoline,reformate and raffinate. Preferably, the hydrocarbon feedstreamcomprises at least one of paraffins, olefins, aromatics, naphthenes, andmixtures thereof, which produces light olefins, hydrogen, lightparaffins, gasoline, and optionally, cracked naphtha, cracked gas oil,tar and coke. Typically, the cracked products from processes inaccordance with the present invention comprise hydrogen, light olefins,light paraffins, and olefins and paraffins having more than five carbonatoms. Products can be liquid and/or gaseous.

The catalyst system of the present invention comprises (1) at least onesolid acid component, (2) at least one metal-based component comprisedof one or more elements from Groups 1 and 2; one or more elements fromGroup 3; and one or more elements from Groups 5–15 of the Periodic Tableof the Elements; and at least one of oxygen and sulfur, and (3) at leastone of at least one support, at least one filler and at least onebinder.

The first two components (1) and (2) of the catalyst system can bepresent as either a physical admixture or chemically bound. Preferably,the elements of the metal-based component are chemically bound.

The solid acid component is described by the Br{acute over (ø)}nsted andLewis definitions of any material capable of donating a proton oraccepting an electron pair. This description can be found in K. Tanabe.Solid Acids and Bases: their catalytic properties. Tokyo: KodanshaScientific, 1970, p. 1–2. This reference is incorporated herein byreference in its entirety. The solid acid component can comprise atleast one of solid acid, supported acid, or mixtures thereof. The solidacid component can comprise nonporous, microporous, mesoporous,macroporous or as a mixture thereof. These porosity designations areIUPAC conventions and are defined in K. S. W. Sing, D. H. Everett, R. A.W. Haul L. Moscou, R. A. Pierotti, J. Rouquérol, T. Siemieniewska,Pure&Appl. Chem. 1995, 57(4), pp. 603–619, which is incorporated hereinby reference in its entirety.

Non-limiting examples of solid acid components are natural clays such askaolinite, bentonite, attapulgite, montmorillonite, clarit, fuller'searth, cation exhange resins and SiO₂.Al₂O₃, B₂O₃.Al₂O₃, Cr₂O₃.Al₂O₃,MoO₃.Al₂O₃, ZrO₂.SiO₂, Ga₂O₃.SiO₂, BeO.SiO₂, MgO.SiO₂, CaO.SiO₂,SrO.SiO₂, Y₂O₃.Si₂, La₂O₃.SiO₂, SnO.SiO₂, PbO.SiO₂, MoO₃.Fe₂(MoO₄)₃,MgO.B₂O₃, TiO₂.ZnO, ZnO, Al₂O₃, TiO₂, CeO₂, As₂O₃, V₂O₅, SiO₂, Cr₂O₃,MoO₃, ZnS, CaS, CaSO₄, MnSO₄, NiSO₄, CuSO₄, CoSO₄, CdSO₄, SrSO₄, ZnSO₄,MgSO₄, FeSO₄, BaSO₄, KHSO₄, K₂SO₄, (NH₄)₂SO₄, Al₂(SO₄)₃, Fe₂(SO₄)₃,Cr₂(SO₄)₃, Ca(NO₃)₂, Bi(NO₃), Zn(NO₃)₂, Fe(NO₃)₃, CaCO₃, BPO₄, FePO₄,CrPO₄, Ti₃(PO₄)₄, Zr₃(PO₄)₄, Cu₃(PO₄)₂, Ni₃(PO₄)₂, AlPO₄, Zn₃(PO₄)₂,Mg₃(PO₄)₂, AlCl₃, TiCl₃, CaCl₂, AgCl₂, CuCl, SnCl₂, CaF₂, BaF₂, AgClO₄,and Mg(ClO₄)₂. Depending on the synthesis conditions, these materialscan be prepared as nonporous, microporous, mesoporous, or macroporuous,as defined in the reference cited above. Conditions necessary to thesepreparations are known to those of ordinary skill in the art.

Non-limiting examples of solid acids can also include both natural andsynthetic molecular sieves. Molecular sieves have silicate-basedstructures (“zeolites”) and AlPO-based structures. Some zeolites aresilicate-based materials which are comprised of a silica lattice and,optionally, alumina combined with exchangeable cations such as alkali oralkaline earth metal ions. For example, faujasites, mordenites andpentasils are non-limiting illustrative examples of such silicate-basedzeolites. Silicate-based zeolites are made of alternating SiO₂ andMO_(x) tetrahedral, where in the formula M is an element selected fromGroups 1 through 16 of the Periodic Table (new IUPAC). These types ofzeolites have 8-, 10- or 12-membered ring zeolites, such as Y, beta,ZSM-5, ZSM-22, ZSM-48 and ZSM-57.

Other silicate-based materials suitable for use in practicing thepresent invention include zeolite bound zeolites as described in WO97/45387, incorporated herein by reference in its entirety. Thesematerials comprise first crystals of an acidic intermediate pore sizefirst zeolite and a binder comprising second crystals of a secondzeolite. Unlike zeolites bound with amorphous material such as silica oralumina to enhance the mechanical strength of the zeolite, the zeolitebound zeolite catalyst does not contain significant amounts ofnon-zeolitic binders.

The first zeolite used in the zeolite bound zeolite catalyst is anintermediate pore size zeolite. Intermediate pore size zeolites have apore size of from about 5 to about 7 Å and include, for example, AEL,MFI, MEL, MFS, MEI, MTW, EUO, MTT, HEU, FER, and TON structure typezeolites. These zeolites are described in Atlas of Zeolite StructureTypes, eds. W. H. Meier and D. H. Olson, Butterworth-Heineman, ThirdEdition, 1992, which is incorporated herein by reference in itsentirety. Non-limiting, illustrative examples of specific intermediatepore size zeolites are ZSM-5, ZSM-11, ZSM-12, ZSM-22, ZSM-23, ZSM-34,ZSM-35, ZSM-38, ZSM-48, ZSM-50 AND ZSM-57. Preferred first zeolites aregalliumsilicate zeolites having an MFI structure and alumiminosilicatezeolites having an MFR structure.

The second zeolite used in the zeolite bound zeolite structure willusually have an intermediate pore size (e.g., about 5.0 to about 5.5 Å)and have less activity than the first zeolite. Preferably, the secondzeolite will be substantially non-acidic and will have the samestructure type as the first zeolite. The preferred second zeolites arealuminosilicate zeolites having a silica to alumina mole ratio greaterthan 100 such as low acidity ZSM-5. If the second zeolite is analuminosilicate zeolite, the second zeolite will generally have a silicato alumina mole ratio greater than 100:1, e.g., 500:1; 1,000:1, etc.,and in some applications will contain no more than trace amounts ofalumina. The second zeolite can also be silicalite, i.e., a MFI typesubstantially free of alumina, or silicalite 2, a MEL type substantiallyfree of alumina. The second zeolite is usually present in the zeolitebound zeolite catalyst in an amount in the range of from about 10% to60% by weight based on the weight of the first zeolite and, morepreferably, from about 20% to about 50% by weight.

The second zeolite crystals preferably have a smaller size than thefirst zeolite crystals and more preferably will have an average particlesize from about 0.1 to about 0.5 microns. The second zeolite crystals,in addition to binding the first zeolite particles and maximizing theperformance of the catalyst will preferably intergrow and form anovergrowth which coats or partially coats the first zeolite crystals.Preferably, the crystals will be resistant to attrition.

The zeolite bound zeolite catalyst is preferably prepared by a threestep procedure. The first step involves the synthesis of the firstzeolite crystals prior to converting it to the zeolite bound zeolitecatalyst. Next, a silica-bound aluminosilicate zeolite can be preparedpreferably by mixing a mixture comprising the aluminosilicate crystals,a silica gel or sol, water and optionally an extrusion aid and,optionally, a metal component until a homogeneous composition in theform of an extrudable paste develops. The final step is the conversionof the silica present in the silica-bound catalyst to a second zeolitewhich serves to bind the first zeolite crystals together.

It is to be understood that the above description of zeolite boundzeolites can be equally applied to non-zeolitic molecular sieves (i.e.,AlPO's).

Other molecular sieve materials suitable for this invention includealuminophosphate-based materials. Aluminophosphate-based materials aremade of alternating AlO4 and PO4 tetrahedra. Members of this family have8- (e.g., AlPO₄-12, -17, -21, -25, -34, -42, etc.) 10- (e.g., AlPO₄-11,41, etc.), or 12- (AlPO₄-5, -31 etc.) membered oxygen ring channels.Although AlPO₄s are neutral, substitution of Al and/or P by cations withlower charge introduces a negative charge in the framework, which iscountered by cations imparting acidity.

By turn, substitution of silicon for P and/or a P-Al pair turns theneutral binary composition (i.e., Al, P) into a series ofacidic-ternary-composition (Si, Al, P) based SAPO materials, such asSAPO-5, -11, -14, -17, -18, -20, -31, -34, -41, -46, etc. Acidic ternarycompositions can also be created by substituting divalent metal ions foraluminum, generating the MeAPO materials. Me is a metal ion which can beselected from the group consisting of, but not limited to Mg, Co, Fe, Znand the like. Acidic materials such as MgAPO (magnesium substituted),CoAPO (cobalt substituted), FeAPO (iron substituted), MnAPO (manganesesubstituted) ZnAPO (zinc substituted) etc. belong to this category.Substitution can also create acidic quaternary-composition basedmaterials such as the MeAPSO series, including FeAPSO (Fe, Al, P, andSi), MgAPSO (Mg, Al, P, Si), MnAPSO, CoAPSO, ZnAPSO (Zn, Al, P, Si),etc. Other substituted aluminophosphate-based materials include ElAPOand ElAPSO (where El=B, As, Be, Ga, Ge, Li, Ti, etc.). As mentionedabove, these materials have the appropriate acidic strength forreactions such as cracking. The more preferred aluminophosphate-basedmaterials include 10- and 12-membered ring materials (SAPO-11, -31, -41;MeAPO-11, -31, -41; MeAPSO-11, -31, 41; ElAPO-11, -31, -41; ElAPSO-11,-31, -41, etc.) which have significant olefin selectivity due to theirchannel structure.

Supported acid materials are either crystalline or amorphous materials,which may or may not be themselves acidic, modified to increase the acidsites on the surface. Non-limiting, illustrative examples are H₂SO₄,H₃PO₄, H₃BO₃, CH₂(COOH)₂, mounted on silica, quartz, sand, alumina ordiatomaceous earth., as well as heteropoly acids mounted on silica,quartz, sand, alumina or diatomaceous earth. Non-limiting, illustrativeexamples of crystalline supported acid materials are acid-treatedmolecular sieves, sulfated zirconia, tungstated zirconia, phosphatedzirconia and phosphated niobia.

Although the term“zeolites” includes materials containing silica andoptionally, alumina, it is recognized that the silica and aluminaportions may be replaced in whole or in part with other oxides. Forexample, germanium oxide, tin oxide, phosphorus oxide, and mixturesthereof can replace the silica portion. Boron, oxide, iron oxide,gallium oxide, indium oxide, and mixtures thereof can replace thealumina portion. Accordingly, “zeolite” as used herein, shall mean notonly materials containing silicon and, optionally, aluminum atoms in thecrystalline lattice structure thereof, but also materials which containsuitable replacement atoms for such silicon and aluminum, such asgallosilicates, borosilicates, ferrosilicates, and the like.

Besides encompassing the materials discussed above, “zeolites” alsoencompasses aluminophosphate-based materials.

Mesoporous solid acids can be ordered and non-ordered. Non-limitingexamples of ordered mesoporous materials include pillared layered clays(PILC's), MCM-41 and MCM-48. Non-limiting examples of non-orderedmesoporous materials include silica and titania-based xerogels andaerogels.

The solid acid component can also be conventional FCC catalyst includingcatalysts containing large-pore zeolite Y, modified zeolite Y, zeolitebeta, and mixtures thereof, and catalysts containing a mixture ofzeolite Y or modified zeolite Y and a medium-pore, shape-selectivemolecular sieve species such as ZSM-5 or modified ZSM-5, or a mixture ofan amorphous acidic material and ZSM-5 or modified ZSM-5. Such catalystsare described in U.S. Pat. No. 5,318,692, incorporated by referenceherein. The zeolite portion of the FCC catalyst particle will typicallycontain from about 5 wt. % to 95 wt. % zeolite-Y (or alternatively theamorphous acidic material) and the balance of the zeolite portion beingZSM-5. Useful medium-pore, shape-selective molecular sieves includezeolites such as ZSM-5, which is described in U.S. Pat. Nos. 3,702,886and 3,770,614. ZSM-11 is described in U.S. Pat. No. 3,709,979; ZSM-12 inU.S. Pat. No. 3,832,449; ZSM-21 and ZSM-38 in U.S. Pat. No. 3,948,758;ZSM-23 in U.S. Pat. No. 4,076,842; and ZSM-35 in U.S. Pat. No.4,016,245. All of the above patents are incorporated herein byreference.

The large pore and shape selective zeolites may include “crystallineadmixtures” which are thought to be the result of faults occurringwithin the crystal or crystalline area during the synthesis of thezeolites. Examples of crystalline admixtures of ZSM-5 and ZSM-11 aredisclosed in U.S. Pat. No. 4,229,424 which is incorporated herein byreference. The crystalline admixtures are themselves medium pore, i.e.,shape selective, size zeolites and are not to be confused with physicaladmixtures of zeolites in which distinct crystals of crystallites ofdifferent zeolites are physically present in the same catalyst compositeor hydrothermal reaction mixtures.

The conventional FCC catalyst may contain other reactive or non-reactivecomponents, such catalysts are described in European patent EP0600686B1,incorporated by reference herein.

The metal-based component of the catalyst system in accordance with thepresent invention is comprised of

-   -   (i) at least one of oxygen and sulfur    -   (ii) one or more elements from Groups 5–15 of the Periodic Table        of the Elements; and    -   (iii) one or more elements from at least one of        -   (a) Groups 1–2 and        -   (b) Group 4; of the Periodic Table of the Elements.            It is intended that reference to an element from each of the            noted Groups would include mixtures of elements from the            respective groups. For example, reference to one or more            element from Groups 1–2 includes a mixture of elements from            Groups 1 and 2 of the Periodic Table.

This metal-based component can adopt a perovskite (ABO₃) crystalstructure, where A and B are two distinct metal sites. Each metal sitecan comprise of one or more metal cations from Group 1–15 of thePeriodic Table of Elements. The crystal structure can be significantlydistorted from the idealized cubic, perovskite structure depending onthe choice of metals at A and B sites and/or due to the formation ofoxygen vacancies upon reduction.

The metal-based component could be prepared, by way of non-limitingexample, by combining salts or chalcogenides (compounds of the Group 16elements) containing the desired parts through such means as evaporationor precipitation, followed by calcination. The solid acid component isthen physically mixed or chemically reacted with the metal-basedcomponent and, optionally, combined with the binder to form catalystparticles.

The preparation of the metal -based component and solid-acid componentare known to those of ordinary skill in the art. The metal-basedcomponent can be obtained through chemical means, such as thecombination of metal salts and/or chalcogenides, in solution or slurry,followed by removal of the solvent or mother liquor via evaporation orfiltration and drying. The metal-based component can then be ground andcalcined. The solid acid and metal-based components can be physicallyadmixed by mechanical mixing.

The element(s) from Groups 1–2 can be any element or a mixture ofelements from Groups 1 and 2 of the Periodic Table of the Elements. Inany event, the element(s) from Groups 1–2 is (are) at least one oflithium, sodium, potassium, rubidium, cesium, beryllium, magnesium,calcium, strontium, and barium. Preferably, the element(s) from Groups 1and 2 is (are) at least one of potassium, magnesium, calcium, strontium,barium.

Preferably, the element(s) from Group 4 are at least one of titanium,zirconium and hafnium.

The element(s) from Groups 5–15 can be any element or a mixture ofelements from Groups 5–15 of the Periodic Table of the Elements.Preferably, the element(s) from Groups 5–15 is (are) at least one of.vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc,boron, aluminum, phosphorous, gallium, germanium, niobium, molybdenum,ruthenium, rhodium, palladium, silver, indium, tin, antimony, tungsten,rhenium, iridium, platinum, gold, lead and bismuth.

The remaining component of the metal-based component of the catalystsystem in accordance with the invention can be at least one of sulfurand oxygen. Oxygen is preferred.

In one aspect of the present invention, the solid acid component and themetal-based component of the catalyst system in accordance with thepresent invention may be physically mixed or chemically bound. Thephysically mixed or the chemically bound materials can then be subjectedto the treatment of a matrix component. The matrix component servesseveral purposes. It can bind the solid acid component and the metalbased component to form catalyst particles. It can serve as a diffusionmedium for the transport of feed and product molecules. It can also actas a filler to moderate the catalyst activity. In addition, the matrixcan help heat transfer or serve as metal sinks.

Examples of typical matrix materials include amorphous compounds such assilica, alumina, silica-alumina, silica-magnesia, titania, zirconia, andmixtures thereof. It is also preferred that separate alumina phases beincorporated into the inorganic oxide matrix. Species of aluminumoxyhydroxides-γ-alumina, boehmite, diaspore, and transitional aluminassuch as α-alumina, β-alumina, γ-alumina, δ-alumina, ε-alumina,κ-alumina, and ρ-alumina can be employed. Preferably, the aluminaspecies is an aluminum trihydroxide such as gibbsite, bayerite,nordstrandite, or doyelite. The matrix material may also containphosphorous or aluminum phosphate. The matrix material may also containclays such as halloysite, kaolinite, bentonite, attapulgite,montmorillonite, clarit, fuller's earth, diatomaceous earth, and mixturethereof. The weight ratio of the solid acid component and themetal-based component to the inorganic oxide matrix component can beabout 100:1 to 1:100.

In another aspect of the present invention, the solid acid component andthe metal-based component of catalysts in accordance with the presentinvention may be treated separately with a matrix component. The matrixcomponent for the solid acid component can be the same as or differentfrom that for the metal-based component. One of the purposes of thetreatment is to form particles of the solid acid component and particlesof the metal-based component so that the components are hard enough tosurvive interparticle and reactor wall collisions. The matrix componentmay be made according to conventional methods from an inorganic oxidesol or gel, which is dried to “glue” the catalyst particle's componentstogether. The matrix component can be catalytically inactive andcomprises oxides of silicon, aluminum, and mixtures thereof. It is alsopreferred that separate alumina phases be incorporated into theinorganic oxide matrix. Species of aluminum oxyhydroxides-γ-alumina,boehmite, diaspore, and transitional aluminas such as α-alumina,β-alumina, γ-alumina, δ-alumina, ε-alumina, κ-alumina, and ρ-alumina canbe employed. Preferably, the alumina species is an aluminum trihydroxidesuch as gibbsite, bayerite, nordstrandite, or doyelite. The matrixmaterial may also contain phosphorous or aluminum phosphate. The matrixmaterial may also contain clays such as kaolinite, bentonite,attapulgite, montmorillonite, clarit, fuller's earth, diatomaceousearth, and mixture thereof.

The weight ratio of the solid acid component to the matrix component canbe about 100:1 to 1:100. The weight ratio of the metal-based componentto the matrix component can be about 100:1 to 1:100

The solid-acid component particles and the metal-based componentparticles may be mixed to form a uniform catalyst system in the reactoror be packed in series to form a staged catalyst system in either asingle reactor or two or more staged reactors.

The catalyst system of the present invention is multifunctional in thatit both cracks a hydrocarbon feedstream and selectively combusts thehydrogen produced from the cracking reaction. The solid acid componentof the catalyst system performs the cracking function and themetal-based component of the catalyst system performs the selectivehydrogen combustion function. The catalyst system is particularlywell-suited for cracking hydrocarbons to light olefins and gasoline.Conventional catalytic cracking generates hydrogen amongst other crackedproducts, which makes products recovery more difficult and costly. Thecatalyst system of the present invention can perform hydrocarboncracking without a substantial co-production of hydrogen therebyreducing the investment and operating costs and/or creating moreequipment volume for higher production capacity.

In accordance with the present invention, a catalyst system comprises ahydrocarbon cracking component and a selective hydrogen combustioncomponent, which catalyst system, upon contact with a hydrocarbonfeedstream, simultaneously cracks the hydrocarbon and selectivelycombusts the hydrogen produced from the cracking reaction. It ispreferred that selective hydrogen combustion is conducted via ananaerobic mechanism which is related to the use of lattice oxygen fromthe selective hydrogen combustion component to promote selectivehydrogen combustion.

Selective hydrogen combustion could also help supply the heat requiredfor hydrocarbon cracking. The combustion of hydrogen is highlyexothermic and, therefore, would be an ideal internal source of heatsupply. This could reduce or even eliminate the need for external heat.

Thus, in accordance with the present invention, a catalytic crackingprocess comprises contacting a hydrocarbon feedstream with a catalystsystem comprising a cracking/selective hydrogen combustion catalystunder suitable catalytic cracking/selective hydrogen combustionconditions to produce olefin, gasoline and other cracked products,wherein the catalytic cracking is conducted in a reduction of addedheat. “Reduction of added heat” is meant that less than 98% of the totalrequired heat input is added. More preferably, less than 95% of thetotal required heat input is added. Most preferably, less than 90% ofthe total required heat input is added. Since cracking reactions areendothermic, the required heat input is simply the overall enthalpy ofthe reaction. Thus, it is within the skill of one of ordinary skill inthe art to calculate the required heat input.

In accordance with the present invention, a free-oxygen containing gassuch as air or pure oxygen can be used as the source of oxygen for theselective hydrogen combustion reaction. The free-oxygen containing gascan be co-fed into the reaction vessel(s) with the hydrocarbonfeedstream. Preferably, the lattice oxygen in the metal-based componentof the catalyst system is used as the source of oxygen for the selectivehydrogen combustion reaction (anaerobic hydrogen combustion). Higherselective hydrogen combustion selectivity and less CO_(x) by-product areachievable using this approach as compared to co-feeding oxygen to thereactor. Using continuous catalyst regeneration technology wouldovercome the potential problem related to lattice oxygen being quicklyconsumed with resultant loss of catalyst activity.

The inventive process can be performed using any known reactor. By wayof non-limiting, illustrative example, fixed-bed reactors with catalystregeneration, moving bed reactors with catalyst regeneration such as thecontinuous catalyst regeneration reactor (also known as CCR),fluidized-bed processes such as a riser reactor with catalystregeneration and the like would be suitable. A non-limiting illustrativeexample of a suitable fixed-bed catalyst regeneration system isillustrated in U.S. Pat. No. 5,059,738 to Beech, Jr. et al, which isincorporated herein by reference in its entirety. A non-limitingillustrative example of a suitable continuous catalyst regenerationmoving bed reactor is illustrated in U.S. Pat. No. 5,935,415 to Haizmannet al, which is incorporated herein by reference in its entirety. Apreferred reactor system would be a downer-regenerator or ariser-regenerator system as described below for illustration purposesonly. A riser-regenerator system that would be suitable for use inpracticing the inventive process is disclosed in U.S. Pat. No.5,002,653, which is incorporated herein by reference in its entirety.

In a riser-regenerator system, pre-heated hydrocarbon feed is contactedwith catalyst in a feed riser line wherein the reaction primarily takesplace. The temperature and pressure for the riser/reactor can be in therange of 300–800° C. and 0.1–10 atmospheres, respectively. The catalystto hydrocarbon feed ratio, weight basis, can be in the range of 0.01 to1000. The residence time in the reaction zone can be in the range of0.01 second to 10 hours. As the reactions progress, the catalyst systemis progressively deactivated due to a number of reasons including theconsumption of lattice oxygen and the formation of coke on the catalystsurface. The catalyst system and hydrocarbon vapors are separatedmechanically and hydrocarbons remaining on the catalyst are removed bysteam stripping before the catalyst system enters a catalystregenerator. The hydrocarbon vapors are taken overhead to a series offractionation towers for product separation. Spent catalyst system isreactivated in the regenerator by burning off coke deposits with air.The coke burn also serves as an oxidation treatment to replenish thecatalyst system's lattice oxygen consumed in the reactor. Thetemperature and pressure for the regenerator can be in the range of300–800° C. and 0.1–10 atmospheres, respectively. As required, a smallamount of fresh make-up catalyst can be added to the reactor.

The cracking process of the present invention may also be performed inone or more conventional FCC process units under conventional FCCconditions in the presence of the catalyst system of this invention.Each unit comprises a riser reactor having a reaction zone, a strippingzone, a catalyst regeneration zone, and at least one fractionation zone.The feed is conducted to the riser reactor where it is injected into thereaction zone wherein the heavy feed contacts a flowing source of hot,regenerated catalyst. The hot catalyst vaporizes and cracks the feed andselectively combusts the resultant hydrogen at a temperature from about475° C. to about 650° C., preferably from about 500° C. to about 600° C.The cracking reaction deposits carbonaceous hydrocarbons, or coke, onthe catalyst system and the selective hydrogen combustion reactiondepletes the lattice oxygen, thereby deactivating the catalyst system.The cracked products may be separated from the deactivated catalystsystem and a portion of the cracked products may be fed to afractionator. The fractionator separates at least a naphtha fractionfrom the cracked products.

The deactivated catalyst system flows through the stripping zone wherevolatiles are stripped from the catalyst particles with a strippingmaterial such as steam. The stripping may be performed under lowseverity conditions in order to retain absorbed hydrocarbons for heatbalance. The stripped catalyst is then conducted to the regenerationzone where it is regenerated by burning coke on the catalyst system andoxidizing the oxygen-depleted metal-based catalyst component in thepresence of an oxygen containing gas, preferably air. Decoking andoxidation restore catalyst activity and simultaneously heats thecatalyst system to, e.g., 650° C. to 800° C. The hot catalyst is thenrecycled to the riser reactor at a point near or just upstream of thesecond reaction zone. Flue gas formed by burning coke in the regeneratormay be treated for removal of particulates and for conversion of carbonmonoxide, after which the flue gas is normally discharged into theatmosphere.

The feed may be cracked in the reaction zone under conventional FCCconditions in the presence of the catalyst system of this invention.Preferred process conditions in the reaction zone include temperaturesfrom about 475° C. to about 650° C., preferably from about 500° C. to600° C.; hydrocarbon partial pressures from about 0.5 to 3.0atmospheres, preferably from about 1.0 to 2.5 atmospheres; and acatalyst to feed (wt/wt) ratio from about 1 to 30, preferably from about3 to 15; where catalyst weight is total weight of the catalystcomposite. Though not required, it is also preferred that steam beconcurrently introduced with the feed into the reaction zone, with thesteam comprising up to about 15 wt. %, and preferably ranging from about1 wt. % to about 5 wt. % of the feed. Also, it is preferred that thefeed's residence time in the reaction zone be less than about 100seconds, for example from about 0.01 to 60 seconds, preferably from 0.1to 30 seconds.

In accordance with the present invention, the weight ratio of solid acidcomponent to the total weight of metal-based component is from 1000:1 to1:1000. More preferably, the ratio is from 500:1 to 1:500. Mostpreferably, the ratio is from 100:1 to 1:100.

EXAMPLES

The invention is illustrated in the following non-limiting examples,which are provided for the purpose of representation, and are not to beconstrued as limiting the scope of the invention. All parts andpercentages in the examples are by weight unless indicated otherwise.

Example 1

This example illustrates the hydrogen yield during hydrocarbon crackingusing a conventional zeolitic catalyst, without the addition ofselective hydrogen combustion (SHC) catalyst. 4.0 grams of OlefinsMax(Grace Davison Division of W.R. Grace & Co.) were pelletized, crushedand screened to 30–50 mesh powder. It was then steamed at 700° C. for 2hours. 1.0 gram of steamed OlefinsMax was then physically mixed with 2.5grams of SiC (16–25 mesh), and loaded into a fixed-bed reactor fortesting. The catalyst was heated to 540° C. in a helium stream at a flowrate of 105 cc/min (cubic centimeters per minute) and a pressure of 2–4psig. The temperature was allowed to stabilize for 30 minutes prior tothe addition of hydrocarbon feed. The feed consisted of 0.384 cc/min of2-methylpentane or Light Virgin Naphtha (LVN) and 0.025 cc/min of liquidwater. Following the introduction of hydrocarbon feed, product sampleswere collected every 30 seconds for a total time-period of 3.5 minutesusing a multi-port, gas-sampling valve. The product was analyzed using agas chromatograph equipped with flame ionization and pulsed dischargedetectors. Table 1 shows the hydrogen and combined yield of C₁–C₄products at various conversions of 2-methylpentane. When LVN was used asfeed, similar hydrogen and C₁–C₄ yields were obtained when compared atthe same feed conversion. A small CO_(x) yield (typically, <0.1 wt %)was observed due to background contamination and/or hydrocarbonoxidation during post-reaction sampling/analysis.

TABLE 1 2-Methylpentane Hydrogen Conversion C₁–C₄ Yield (wt %) Yield (wt%) 39.2 33.3 0.230 ± 0.012 21.1 18.6 0.131 ± 0.007 8.1 6.7 0.044 ± 0.002

Example 2

This example illustrates the preparation and performance of selectivehydrogen combustion (SHC) catalyst for reducing the hydrogen yield inthe product, while minimizing non-selective hydrocarbon oxidation.In_(0.8)Ca_(0.2)MnO₃ catalyst was prepared by co-precipitation of metalsalts using an organic base and a carbonate precursor. Solution A wasprepared by dissolving 6.289 grams of indium nitrate hydrate (AlfaAesar, Ward Hill, Mass.), 1.164 grams of calcium nitrate tetrahydrate(Alfa Aesar, Ward Hill, Mass.), and 7.018 grams of manganese(II) nitratehydrate (Aldrich Chemical Company, Milwaukee, Wis.) in 247 grams ofdeionized water. Solution B was prepared by dissolving 15.0 grams ofsodium bicarbonate (Mallinckrodt Baker Inc., Paris, Ky.), 45.1 grams oftetraethylammonium hydroxide, 35 wt % solution (Alfa Aesar, Ward Hill,Mass.) in 715 grams of deionized water. Solution A was slowed pouredinto a well-stirred solution B, resulting in precipitate formation.After aging the suspension for 1 hour, the particles were recovered bycentrifugation at 1500–2000 rpm. The precipitate was then resuspended in250 mL of isopropanol (VWR Scientific Products Corporation, Chicago,Ill.) followed by centrifugation to remove water, impuritycations/anions. This washing step was repeated to ensure completeremoval of impurities. The precipitate was dried in air at 25° C.,ground to a fine powder using a mortar and pestle, and calcined to 800°C. for 2 hours in air. The sample was pelletized, crushed, and screenedto 30–50 mesh prior to SHC testing.

1.0 grams of steamed OlefinsMax (prepared as described in Example 1) wasphysically mixed with 0.5 grams of SHC catalyst and 2.0 gram of SiC, andloaded into a fixed bed reactor. All other testing conditions were keptthe same as in Example 1. Table 2 shows the results of the SHC test.

TABLE 2 SHC Catalyst In_(0.8)Ca_(0.2)MnO₃ % Conversion 20.9 C1–C4 Yield(wt %) 16.2 H₂ Yield (wt %) 0.011 % H₂ Conversion 92 CO_(x) Yield (wt %)0.220 % H₂ Selectivity 85

The data in Table 2 demonstrates that significant reductions in hydrogenyield can be achieved through the addition of SHC catalyst. Compared toExample 1, there is a 92 percent reduction in hydrogen yield at similarhydrocarbon conversion and C1–C4 yields. Moreover, the SHC catalystexhibits a high selectivity of 85 percent for hydrogen combustion,resulting in minimal CO_(x) formation through non-selective hydrocarbonactivation.

Example 3

This example illustrates the preparation and performance of selectivehydrogen combustion (SHC) catalyst for reducing the hydrogen yield inthe product, while minimizing non-selective hydrocarbon oxidation.Bi_(0.4)Ca_(0.6)Mn_(0.6)Ni_(0.4)O₃ catalyst was prepared byco-precipitation of metal salts using an organic base in alcoholicmedium. Solution A was prepared by adding 5 mL of concentrated nitricacid to 50 mL of deionized water. 4.574 grams of bismuth nitratepentahydrate (Aldrich Chemical Company, Milwaukee, Wis.) were added tothis solution and stirred for 10 minutes to allow complete dissolution.3.341 grams of calcium nitrate tetrahydrate (Alfa Aesar, Ward Hill,Mass.), 4.027 grams of manganese(II) nitrate hydrate (Aldrich ChemicalCompany, Milwaukee, Wis.), 2.742 of nickel(II) nitrate hexahydrate(Aldrich Chemical Company, Milwaukee, Wis.) and 107 grams of deionizedwater were then added and dissolved in solution A. Solution B wasprepared by dissolving 98 grams of tetraethylammonium hydroxide, 35 wt %solution (Alfa Aesar, Ward Hill, Mass.) in 534 grams of isopropanol (VWRScientific Products Corporation, Chicago, Ill.). Solution A was slowedpoured into a well-stirred solution B, resulting in precipitateformation. After aging the suspension for 1 hour, the particles wererecovered by centrifugation at 1500–2000 rpm. The precipitate was thenresuspended in 250 mL of isopropanol followed by centrifugation toremove water, impurity cations/anions. The precipitate was dried in airat 25° C., ground to a fine powder using a mortar and pestle, andcalcined to 750° C. for 2 hours in air. The sample was pelletized,crushed, and screened to 30–50 mesh prior to SHC testing.

1.0 grams of steamed OlefinsMax (prepared as described in Example 1) wasphysically mixed with 0.5 grams of SHC catalyst and 2.0 gram of SiC, andloaded into a fixed bed reactor. All other testing conditions were keptthe same as in Example 1. Table 3 shows the results of the SHC test.

TABLE 3 SHC Catalyst Bi_(0.4)Ca_(0.6)Mn_(0.6)Ni_(0.4)O₃ % Conversion 8.1C1–C4 Yield (wt %) 6.7 H₂ Yield (wt %) 0.0076 % H₂ Conversion 83 CO_(x)Yield (wt %) 0.129 % H₂ Selectivity 80

The date in Table 3 demonstrates that significant reductions in hydrogenyield can be achieved through the addition of SHC catalyst. Compared toExample 1, there is a 83 percent reduction in hydrogen yield at similarhydrocarbon conversion and C1–C4 yields. Moreover, the SHC catalystexhibits a high selectivity of 80 percent for hydrogen combustion,resulting in minimal CO_(x) formation through non-selective hydrocarbonactivation.

Example 4

This example illustrates the preparation and performance of selectivehydrogen combustion (SHC) catalyst for reducing the hydrogen yield inthe product, while minimizing non-selective hydrocarbon oxidation.Ca_(0.6)Na_(0.4)SnO₃ catalyst was prepared by co-precipitation of metalsalts using an organic base in alcoholic medium. Solution A was preparedby adding 5 mL of concentrated nitric acid to 50 mL of deionized water.13.151 grams of tin chloride pentahydrate (Alfa Aesar, Ward Hill, Mass.)were added to this solution and stirred for 10 minutes to allow completedissolution. 5.315 grams of calcium nitrate tetrahydrate (Alfa Aesar,Ward Hill, Mass.) and 260 grams of deionized water were then added anddissolved in solution A. Solution B was prepared by dissolving 164 gramsof tetraethylammonium hydroxide, 35 wt % solution (Alfa Aesar, WardHill, Mass.) in 637 grams of isopropanol (VWR Scientific ProductsCorporation, Chicago, Ill.). Solution A was slowed poured into awell-stirred solution B, resulting in precipitate formation. After agingthe suspension for 1 hour, the particles were recovered bycentrifugation at 1500–2000 rpm. The precipitate was then resuspended in250 mL of isopropanol followed by centrifugation to remove water,impurity cations/anions. A 0.07295 g Na/g solution was prepared bydissolving NaOH (Mallinckrodt Baker Inc., Paris, Ky.) in deionizedwater. 7.40 grams of NaOH solution and 100 mL of ethanol (Alfa Aesar,Ward Hill, Mass.) were added to the precipitate, and stirred to obtain ahomogenous suspension. The suspension was heated to 90° C. to evaporatethe ethanol, ground using a mortar and pestle to obtain a fine powder,and calcined to 800° C. for 2 hours in air. The sample was pelletized,crushed, and screened to 30–50 mesh prior to SHC testing.

1.0 grams of steamed OlefinsMax (prepared as described in Example 1) wasphysically mixed with 0.5 grams of SHC catalyst and 2.0 gram of SiC, andloaded into a fixed bed reactor. All other testing conditions were keptthe same as in Example 1. Table 4 shows the results of the SHC test.

TABLE 4 SHC Catalyst Ca_(0.6)Na_(0.4)SnO₃ % Conversion 7.9 C1–C4 Yield(wt %) 6.7 H₂ Yield (wt %) 0.034 % H₂ Conversion 22 CO_(x) Yield (wt %)0 % H₂ Selectivity 100

The data in Table 4 demonstrates that significant reductions in hydrogenyield can be achieved through the addition of SHC catalyst. Compared toExample 1, there is a 22 percent reduction in hydrogen yield at similarhydrocarbon conversion and C1–C4 yields. Moreover, the SHC catalystexhibits a very high selectivity of 100 percent for hydrogen combustion,resulting in no CO_(x) formation through non-selective hydrocarbonactivation.

1. A process for treating a hydrocarbon feedstream comprisingsimultaneously contacting the feedstream under cracking conditions witha catalyst system comprising (1) at least one molecular sieve, (2) atleast one metal-based component comprised of (i) at least one of oxygenand sulfur; (ii) one or more elements from Groups 5–15 of the PeriodicTable of the Elements; and (iii) one or more elements from at least oneof (a) Groups 1–2 and (b) Group 4; of the Periodic Table of theElements; and (3) at least one of at least one support, at least onefiller and at least one binder, wherein the hydrocarbon feedstream iscracked and the resultant hydrogen simultaneously combusted, saidprocess further characterized by anaerobic selective hydrogencombustion, wherein the yield of hydrogen is less than the yield ofhydrogen when contacting said hydrocarbon feedstream with said molecularsieve component alone under said catalytic reaction conditions, toproduce liquid and gaseous hydrocarbons.
 2. The process of claim 1,wherein the catalyst system is regenerated periodically.
 3. The processof claim 1, wherein the molecular sieve component is in physicaladmixture with the metal-based component, and wherein the elements from(i), (ii) and (iii) are chemically bound.
 4. The process of claim 1,wherein the molecular sieve component and the metal-base component arechemically bound, and wherein the elements from (i), (ii) and (iii) arechemically bound.
 5. The catalyst system of claim 1, wherein themolecular sieve comprises at least one zeolite.
 6. The catalyst systemof claim 5, wherein the zeolite comprises at least one of MFI andfaujasite.
 7. The catalyst system of claim 6, wherein the zeolitecomprises at least one of ZSM-5 and Y zeolite.
 8. The process of claim1, wherein the weight ratio of molecular sieve component to the totalweight of metal-based component is 1:1000 to 1000:1.
 9. The process ofclaim 8, wherein the process temperature is from 300–800° C.
 10. Theprocess of claim 9, wherein the process pressure is from 0.1 to 10atmospheres.
 11. The process of claim 10, wherein the catalyst system tooil ratio is from 0.01 to
 1000. 12. The process of claim 11, wherein theresidence time is from 0.01 second to 10 hours.
 13. The process of claim1, wherein the catalyst system comprises a physical mixture of at leastone cracking catalyst and at least one selective hydrogen combustioncatalyst.
 14. The process of claim 1, wherein the cracking catalyst isat least one of at least one fluid catalytic cracking base catalyst, atleast one fluid catalytic cracking additive catalyst, and mixturethereof.
 15. The process of claim 1, wherein the catalyst systemcomprises at least one cracking catalyst chemically bound to at leastone selective hydrogen combustion catalyst.
 16. The process of claim 15,wherein the cracking catalyst is at least one of at least one fluidcatalytic cracking base catalyst, at least one fluid catalytic crackingadditive catalyst, and mixture thereof.
 17. The process of claim 1,conducted in reduction of added heat.
 18. The process of claim 1,wherein the yield of hydrogen is at least 10% less than the yield ofhydrogen when contacting said hydrocarbon feedstream(s) with said solidacid component alone under said catalytic reaction conditions.
 19. Theprocess of claim 1, wherein the yield of hydrogen is at least 25% lessthan the yield of hydrogen when contacting said hydrocarbonfeedstream(s) with said solid acid component alone under said catalyticreaction conditions.
 20. The process of claim 1, wherein the yield ofhydrogen is at least 50% a less than the yield of hydrogen whencontacting said hydrocarbon feedstream(s) with said solid acid componentalone under said catalytic reaction conditions.
 21. The process of claim1, wherein the yield of hydrogen is at least 75% less than the yield ofhydrogen when contacting said hydrocarbon feedstream(s) with said solidacid component alone under said catalytic reaction conditions.
 22. Theprocess of claim 1, wherein the yield of hydrogen is at least 90% lossthan the yield of hydrogen when contacting said hydrocarbonfeedstream(s) with said solid acid component alone under said catalyticreaction conditions.
 23. The process of claim 1, wherein the yield ofhydrogen is greater than 99% less than the yield of hydrogen whencontacting said hydrocarbon feedstream(s) with said solid acid componentalone under said catalytic reaction conditions.
 24. The process of claim1, wherein the hydrocarbon feedstream comprises at least one of gas oil,steam cracked gas oil and residues; heavy hydrocarbonaceous oilscomprising materials boiling above 566° C.; heavy and reduced petroleumcrude oil, petroleum atmospheric distillation bottom, petroleum vacuumdistillation bottom, heating oil, pitch, asphalt, bitumen, other heavyhydrocarbon residues, tar sand oils, shale oil, liquid products derivedfrom coal liquefaction processes, steam heating oil, jet fuel, diesel,kerosene, gasoline, coker naphtha, steam cracked naphtha, catalyticallycracked naphtha, hydrocrackate, reformate, raffinate reformate,Fischer-Tropsch liquids, Fischer-Tropsch gases, natural gasoline,distillate, virgin naphtha, C₅₊ olefins, C₅₊ paraffins, exhane, propane,butanes, butenes and butadiene, olefinic and paraffinic feeds.
 25. Theprocess of claim 1, wherein the feedstream comprises at least one ofparaffins, olefins, aromatics, and naphthenes.
 26. The process of claim1, wherein (ii) is selected from the group consisting of vanadium,chromium, manganese, iron, cobalt, nickel, copper, zinc, boron,aluminum, phosphorous, gallium, germanium, niobium, molybdenum,ruthenium, rhodium, palladium, silver, indium, tin, antimony, tungsten,rhenium, iridium, platinum, gold, lead and bismuth and (iii) is selectedfrom the group consisting of lithium, sodium, potassium, rubidium,cesium, beryllium, magnesium, calcium, strontium, and barium titanium,zirconium and hafnium, wherein said metal-based component adopts aperovskite crystal structure, and wherein said process further comprisessimultaneous cracking and anaerobic hydrogen combustion on contact ofsaid feedstream with said catalyst system.
 27. The process of claim 1,wherein said metal-based component comprises a perovskite crystalstructure having metals selected from the group consisting of: (a) In,Ca, and Mn; (b) Bi, Ca, Mn, Ni; and (c) Ca, Na, and Sn.
 28. The processof claim 1, wherein said metal-based component comprises a perovskitecrystal structure having metals selected from the group consisting of:(a) In, Ca, and Mn; (5) Bi, Ca, Mn, Ni; and (c) Ca, Na, and Sn.
 29. Theprocess of claim 1, wherein said metal-based component comprises aperovskite crystal structure having metals selected from the groupconsisting of: (a) In, Ca, and Mn; (5) Bi, Ca, Mn, Ni; and (c) Ca, Na,and Sn.
 30. The process of claim 1, wherein said metal-based componentcomprises a perovskite crystal structure having metals selected from (i)one or more elements from the group consisting of vanadium, chromium,manganese, iron, cobalt, nickel, copper, zinc, boron, aluminum,phosphorous, gallium, germanium, niobium, molybdenum, ruthenium,rhodium, palladium, silver, indium, tin, antimony, tungsten, rhenium,iridium, platinum, gold, lead and bismuth; and (ii) one or more elementsfrom the group consisting of lithium, sodium, potassium, rubidium,cesium, beryllium, magnesium, calcium, strontium, barium, titanium,zirconium and hafnium.
 31. The process of claim 1, wherein saidselective hydrogen combustion occurs at a temperature of between fromabout 475° C. to about 650° C.
 32. The process of claim 1, wherein saidselective hydrogen combustion occurs at a temperature of between fromabout 500° C. to about 600° C.